BS EN 4540-2011 pdf download.Aerospace series Bearings, spherical plain, in corrosion resisting steel with selflubricating liner elevated load under low oscillations Technical specification.
This BS EN 4540 applies whenever referenced.
These bearings prEN 4538-1, prEN 4538-2, prEN 4539-1 and prEN 4539-2 are for actuator applications and for use in the temperature range — 54 C to 163 C and for EN 4538-003 and EN 4539-003 for use in the temperature range —54 °C to 120 °C.
The liner may be of a fabric or composite material bonded to the inside diameter of the outer ring or in a composite material moulded into a pre-formed cavity between the inner and outer rings.
The duty cycle (Annex E. normative) has been established on the basis of a civil aircraft aileron surface application.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
prEN 4538-1, Aerospace series — Bearings, spherical plain, in corrosion resisting steel with self-lubricating liner — Elevated load under low oscillations — Narrow series — Dimensions and loads — Metric series 1)
prEN 4538-2, Aerospace series — Bearings, spherical plain, in corrosion resisting steel with self-lubricating liner — Elevated load under low oscillations — Narrow series — Dimensions and loads — inch series 1)
EN 4538-003, Aerospace series — Bearings, spherical plain, in corrosion resisting steel with self-lubricating liner elevated load under low oscillations — Narrow series — Dimensions arid loads — Part 003: Inch series with low friction coefficient
prEN 4539-1, Aerospace series — Bearings, spherical plain, in corrosion resisting steel with self-lubricating liner — Elevated load under low oscillations — Wide series — Dimensions and loads — Metric series ‘I)
prEN 4539-2, Aerospace series — Bearings, spherical plain, in corrosion resisting steel with self-lubricating liner — Elevated load under low oscillations — Wide series — Dimensions and loads — Inch series 1)
EN 4539-003, Aerospace series – Bearings, spherical plain. in corrosion resisting steel with self-lubricating liner elevated load under low oscillations – Wide series – Dimensions and loads – Part 003: Inch series with low friction coefficient
EN 9133, Aerospace series — Quality management systems — Qualification procedure for aerospace standard parts
ISO 11078, Aircraft — De-icing/anti-icing fluids, ISO types II. Ill and IV
TR 4475, Aerospace series — Bearings and mechanical transmissions for aiiframe applications — Vocabulary²).
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
self-lubricated spherical plain bearings, self-aligning in corrosion resistant steel with staking groove for actuator applications
these consist of two concentric rings, between which is interposed a self-lubricating liner which is bonded or moulded on the spherical surface of the outer nng.
The width of the inner ring is greater than the width of the outer ring, so that a tilting movement is possible in addition to the rotational movement.
The outer ring has no assembly slot.
This outer ring has grooves for mechanical swaging
3.2
surface discontinulties
see TR 4475
3.3
starting torque without load see TR4475
3.4
friction coefficient
the friction coefficient of the bearing under load is given by the following formula:
where
p friction coefficient;
C torque moment;
F load on the bearing;
R Inner spherical ball radius.
3.5
permissible radial static loads radial ((i)
this corresponds to a permissible unit pressure multiplied by the projected surface area, the inner ring being able to take any position within the limits of the tilting angle indicated in the product standards or design documentation.
3.6
dynamic radial load (oscillatory duty cycles)
load which may be withstood by a bearing submitted to an oscillating movement following a given number arid frequency of cycles, without the wear of the self-lubricating liner exceeding the values given in this standard
3.6.1
oscillating duty cycles
are defined in Annex E. The table defines unit pressure applied.
The dynamic radial load is defined for each bearing size by multiplying the unit pressure by the projected surface area, see dimensional standard
3.6.2
dynamic radial load C25
one oscillating cycle includes an angular displacement of the inner ring in relation to the outer ring from 0° to 25o, then from 25° to — 25° and finally — 25° to 0°
3.6.3
dynamic radial load ‘23O
one oscillating cycle includes an angular displacement of the inner ring in relation to the outer ring from 0° to 25°, then from 25° to — 25° and finally — 25° to 0°
3.7
adhesion of the liner – Void
area where the adhesive bond is broken or non-existent and leaves a smooth and clean interface on the metallic surface
3.8
delivery batch
this consists of bearings with the same identity block, which may come from different production batches.BS EN 4540-2011 pdf download.